A single action revolver is known, in which the hammer, normally actuated by the thumb of the hand, also produces the rotation of the drum. In such a revolver, firing is caused by a subsequent and distinct movement of the index finger of the hand that presses the trigger. Such a type of revolver is recommended for target shooting.
A double-action revolver is also known in which firing is produced by simply pulling the trigger. Such a type of revolver, on the other hand, is much more highly recommended for firing many shots in quick succession even without much precision.
In known revolvers, the recoil force that is generated at the moment of firing produces a moment of rotation on the hand that is substantially proportional to the distance between the axis of the barrel and the median axis of the forearm. The greater such a distance, the greater the tendency of the pistol to recoil or rotate. Therefore at each shot the firearm tends to push down into the hand and tends to rotate between thumb and index finger forcing the firer to take aim once again.
Moreover, in known revolvers, in normal holding of the firearm, the barrel points downwards and can only be taken into horizontal alignment with a considered twist of the wrist upwards. This substantially complicates instinctive shooting.
In order to reduce the recoil of the firearm it has been proposed t bring the barrel into alignment with the lower firing chamber of the drum. However, this has also brought about the lowering both of the hammer and of the relative actuation mechanism and consequently of the point at which the hand rests, which has partially made the advantage achieved futile.
A further drawback of known revolvers is linked to the weight of the firearm.
To reduce the weight of the firearm it has notoriously been attempted to make the fore-end from a light and easily workable material like an aluminum-based alloy, but one is yet to find a light and easily workable material that can at the same time offer high mechanical strength.
With current materials, after a certain number of shots, there is a deformation of the upper transom of the window of the drum that makes the firearm unusable.
The use of titanium and its alloys has been proposed, which is suitable in terms of mechanical strength and lightness but not highly recommended due to cost and workability.
Another drawback of known revolvers is linked to their bulk, for which reason they are generally longer than semi-automatic pistols with the same barrel length.
To compact the firearm a division of the trigger has been proposed by operatively connecting an inner trigger or distributor to the outer trigger, suitable for locking, unlocking and rotating the drum, arming and unhooking the hammer. In this case the outer trigger is suitable just for transmitting the movement of the finger to the distributor through a connecting rod between the two parts.